It is important in high-speed wireless transmission to increase signal transmission efficiency by performing flexible transmission control that can accommodate various types of traffic. Frequency scheduling in MC-CDM (Multi Carrier-Code Division Multiplexing) is investigated in Non-patent Document 1, for example. In the frequency scheduling disclosed therein, a base station selects a subcarrier having a good channel based on reception quality such as the SINR (Signal to Interference and Noise Ratio) reported from a plurality of terminals, and transmits data. Each user uses a subcarrier having a good channel state, and communication at a small PER (Packet Error Rate) is therefore possible.
A method taking into consideration a delay request of a user is proposed in Patent Document 1 as a traffic control technique that takes into consideration a delay request of a user. More specifically, in the case of a connection that has a strict request for a transmission delay, a circuit exchange connection is assigned that accompanies a bandwidth that can be automatically controlled. After resources are assigned to the circuit exchange connection, resources for transmitting a given quantity of data are assigned from an unspecified resource pool by a time-limited based assignment to a connection that has a high allowable delay with respect to each assignment cycle.    Patent Document 1: Japanese Patent Application Publication No. 2001-512939    Non-patent Document 1: “MC-CDM System for Packet Communications Using Frequency Scheduling,” Technical Report of the Institute of Electronics, Information and Communication Engineers of Japan, RSC2002-129 (2002-07).